This is super annoying.
Something keeps me up one night, so on subsequent nights I start thinking that same thing will keep me up. So now it’s the anticipation of something keeping me up that is keeping me up.
This goes on for a few nights until I finally realize that something keeping me up is not worth keeping me up. I forget about it for a while and then I forget it ever existed.
Then it happens again and the cycle begins anew. Each time feels like the very first, because even though I’ve been through this before, that something keeping me up still keeps me up.